Generation III External Engine LS1 | LS6 | Bolt-Ons | Intakes | Exhaust | Ignition | Accessories
Sponsored by:
Sponsored by:

LS2 throttle body voltage readings?

Thread Tools
 
Search this Thread
 
Old Aug 15, 2024 | 12:38 PM
  #1  
Rockitansky's Avatar
Thread Starter
Teching In
 
Joined: Jun 2021
Posts: 35
Likes: 2
Default LS2 throttle body voltage readings?

Hi all, I have a 2002 manual trans corvette with 2002 PCM, LS3 stock engine and LS2 throttle body. I got a few codes P1220 Throttle Position Sensor 1 circuit and so on. At track after about 5 laps car would go into limp mode.

Put the Tech2 on it and got these readings. These are my readings with IGN ON only.
It appears my 0% throttle on TPS sensor 1 is too HI at 1.35volts, but within parameters at WOT at 4.45v.
LS2 TB TPS sensor 1 limits are 0% throttle 0.13v to 0.67v.

My TPS sensor 2 reads 3.67v at 0% throttle, which is too LOW. And WOT reads 0.57v which is within limits.
LS2 TB TPS sensor 2 limits are 0% throttle 4.30v to 4.80v.

Now with ENG running the TPS 1 readings go down to 0.86v at 0% throttle but still too HI by about 0.20v.

Could this cause a Limp mode or other problems? And if so any recommendations on how to fix this?
I have no current DTCs using Tech2, I only got the DTCs when on track romping on it hard.
Battery volts read 13.6 v. THX ALL Brian!


Ignition ON:

IGN ON

Running


ENG RUNNING

TB Voltages
Reply
Old Aug 15, 2024 | 04:48 PM
  #2  
AJG87's Avatar
Launching!
15 Year Member
Photogenic
Photoriffic
Liked
iTrader: (43)
 
Joined: Jun 2007
Posts: 202
Likes: 7
From: The Mitten
Default

Just wondering - Are you using a true GM OEM LS2 unit? I've only ever heard a handful of the OEM units faulting.
Reply
Old Aug 16, 2024 | 08:00 AM
  #3  
Rockitansky's Avatar
Thread Starter
Teching In
 
Joined: Jun 2021
Posts: 35
Likes: 2
Default

Yes its a real OEM GM TB. I even tried another GM TB on my car and got same voltage readings. Car does have a 10% underdrive pulley so alternator is turning slower, but alt still puts out 13.6v at idle. I am thoroughly confused.....
Reply
Old Aug 19, 2024 | 06:38 PM
  #4  
LilJayV10's Avatar
TECH Senior Member
15 Year Member
Liked
Loved
Community Favorite
iTrader: (39)
 
Joined: Apr 2007
Posts: 9,711
Likes: 999
From: Evansville,IN
Default

What does the freeze frame data show?
Reply




All times are GMT -5. The time now is 12:23 PM.

story-0
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?

Slideshow: We take a close look at the ONE and Artidiag 800BT2 diagnostic tools from Topdon and the reasons to buy one over the other.

By Pouria Savadkouei | 2026-05-28 11:05:11


VIEW MORE
story-1
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine

Slideshow: The controversial Ferrari F6 swaps its original flat-12 for a Corvette Z06-derived LT4 V8 and sends power to four rear wheels through a custom-built drivetrain.

By Verdad Gallardo | 2026-05-26 18:23:54


VIEW MORE
story-2
7 Most Reliable High-Performance Engines GM Has Ever Built

Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.

By Verdad Gallardo | 2026-05-21 16:45:27


VIEW MORE
story-3
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-4
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-5
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-6
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-7
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-8
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-9
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE